It is well-known in the automotive door hinge art to provide check spring mechanisms which function to exert a force on the portion of a hinge carrying the door to control movement to and away from the fully opened position of the door. For example, one automotive manufacturer employs a hinge in certain automobiles it produces which includes a bent-over strike tang on the door portion of the hinge which slides along and compresses a leaf spring member carried on the body portion of the hinge to control movement about the fully opened position. While this has been shown to be a simple and effective mechanism, lubrication is required for easy and quiet operation, and the maintaining of contact with the leaf spring during hold open operation increases the cyclic stress life requirements of the components.
Other examples of prior art hinges may be seen in U.S. Pat. No. 3,370,317 to Marchione and U.S. Pat. No. 3,931,664 to Makano, et al. These devices both disclose rather complex structures employing rollers engaging the check spring. Both are disadvantageously complex for some applications and the latter requires significant lubrication to facilitate the long rolling contact of its rollers with its spring.
Another example of a door hinge with an integral check is U.S. Pat. No. 4,532,675 issued to Salazar. This automotive door hinge assembly provides a hold-open device consisting of a leaf spring carried on the body part of the hinge and a roller carried in a cage portion of the door part which engages the leaf spring only during the portion of its travel proximate the door-open position. The roller in this door hinge is disclosed as preferably formed from reinforced nylon. While this has been shown to be a simple and effective mechanism, it has been found that the reinforced nylon roller typically does not wear in a uniform manner about its circumferential periphery. As a result, the reinforced nylon roller begins to contact the leaf spring in the same position during the open and close cycle, thereby wearing down particular portions of the cylindrical circumference, which results in a loss of the door check means for holding the door in the open position after repeated cycling of the mechanism.
A compound roller structure was first described in U.S. Pat. No. 5,018,243 assigned to the same assignee as the present invention. In this compound roller structure, various roller configurations were disclosed with multi-piece spools having two longitudinally spaced, enlarged diameter, annular shoulders to contact the spring and one reduced diameter annular shoulder interposed between the two enlarged shoulders for receiving the pliable annular ring. In the alternative, this patent also disclosed a compound roller structure having a single one piece spool that included one enlarged diameter, annular shoulder to contact the spring and a reduced diameter, annular shoulder to receive the pliable annular ring.